Along with the progress of technology, the illuminating performance of compact type fluorescent lamps has already met the requirements for illumination and such lamps have been employed in various places. The long afterglow illuminating materials are widely used in indicative situations that include those in the realm of fire service, marine vessel, architecture, traffic, railroad and military or the like.
In the realm of the fire service, an indication of an escape way can provide guide directions and allow people in an emergency to find the way out whenever an emergency or a power breakdown occurs. However, it is not enough to have only the indication of directions at stairways, underground and interior corridors of a large building. Because in such places there is nearly no natural light, people are unable to see the way under their feet, thus easily leading to a chaotic situation. Objectively, there is a need to have an illuminating lamp, by which the illumination effect is still maintained to a certain extent even after the power turns off. An illuminating lamp having a long afterglow characteristic was thus designed to meet such a requirement.
Presently, the manufacturing process of the illuminating lamp having a long afterglow characteristic is as follows: during the manufacturing of the fluorescent lamp tube, a layer of long afterglow illuminating material needs first to be applied on the interior of the glass tube before the coating of the fluorescent powder. Since the long afterglow illuminating material is coated on the interior of the glass tube, such a procedure for doing so is complex and the requirement for the thickness and the homogeneity of the coating layer is higher. In addition, a high purity long afterglow illuminating material is required because impurities therein will affect the operation of the lamp tube. By using such a method, the manufacturing cost of the fluorescent lamp having the long afterglow characteristic is relatively high.